Unloader for compressors



I June 15, 1937.

E. M. PAULLIN, JR

UNLOADER FOR GOMPRESSORS Filed Oct. 9, 1934 2 Sheets-Shet 1 EMPauI/i/M IN YEN T OR A TTORNE Y June 15, 1937. E. M. PAULLIN, JR 2,083,740

UNLOADER FOR COMPRES SORS Filed Oct. 9, 1934 2 Sheets-Sheet 2 EMPaal/z'zzJf INVENTOR A TTORNE Y Patented June 15, 1 937 UNLOADER FOR COMPRESSORS Edward M. Paullin, Jr., Buffalo, N. Y., assignor to Worthington Pump and Machinery Corporation, New York, N. Y., a corporation oi Virginia Application October 9. 1934, Serial No. 747,529

4 Claims.

This invention relates to unloaders for compressors and an object of the present invention is to provide a simple, practical and positive loading and unloading mechanism for compressors of relatively small capacity, which will be positive in action and M11 unload the compressor upon the cutting off of operating power thereto and will load the compressor upon the cutting in of operating power.

Another object of the present invention is to provide electrically operated means controlling the loading and unloading of the compressor, which means embodies a mechanism to provide a time lapse between the starting of the com- 15 pressor and its loading, thereby allowing the compressor and its operating motor to reach full speed before the load torque is imposed.

With these and other objects in viewas may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing an unloader for compressors of the preferred form, and the features forming the invention will be specifically pointed out in the claims.

' In the drawings:

Fig. 1 is a diagrammatic view partly insection showing the improved compressor'unload- 30 ing mechanism.

Fig. 2 is a diagrammatic view partly. in section showing a modified form of the compressor unloading mechanism Referring more particularly to the drawings,

5 a reciprocating compressor I, of any approved type, and of relatively small capacity, is shown, which includes the piston 2, suction valve 3 and discharge valve 4. The compressor i is driven 5 ergizing oi the motor 5 and consequently the 55 which by an electric motor 5 in the usual manner, that 40 is, through anysuitable power transmitting means or coupling. s

The compressor I discharges through the pipe I to the receiver Land a check valve 8 is positioned in the pipe 6. The energizing and deenoperation of. the compressor I is controlled by any approved type of control switch III which cuts in and out suitable electric current from the line'wires H. i 1

.To provide for the unloading of'the compressor uponthe'sto'pping ofmits operation and for the loading-of thecompressor upon the starting, the

unloading mechanism l2J -is'provided;v Theun- I loading mechanism 12 comprises avalve. l3 includes a .valve cylinder i4- inawhich is provided a valve seat-i5 against which the valve cone? I6 rests. vA pipe 11 connects to thepipe 6 between .acompressor discharge valve 4 and the check valve 8 and it opens into the cylinder I4 on one side of the valve seat I5. a vent openwill permit the motor .5 to fore the application of the .Th'enunloading :mechanism' and 'apparatus'fillustrated in'Fi'g. l and above described,-is}applicable for compressors of: relatively small-size and ing I8 is formed in the valve cylinder l4 on the opposite side of the valve seat I from the connection between the cylinder l4 and the pipe II. The vent opening/I8 may either open to atmosphere or it may be connected to the suction inlet of the compressor. V

A valve stem [9 is connected to the valve cone l6 and projects upwardly out of the valve cylinder l4 having its upper end positioned inf-the path of the valve operating arm 20. The valve operating arm 20 is pivotally mounted as shown at 2i and is connected to the stem 22 of the solenoid operated structure 23. The solenoid operated structure 23 and the arm 20 may be anyv approved type of construction such as that shown in my companion application, Serial No. 747,528,.filed of even date herewith." The solenoid 24 is connected in the line 25 which supplies power to the motor 5 ,between the motor 5 and the switch l0 so that the solenoid 24 will be energized when the motor 5 is energized. When the motor 5 is deener'gized, and consequently 18 to permit the bleeding of the pressure fluid out of the pipe 6 and the discharge space 4' for unloading the compressor. 'When the switch Iii is closed, to start the compressonthe core 26 will move upwardly which will release the arm for upward movement. The arm 20 is moved upwardly by the spring 21; however, its upward movement is retarded by the action of the dashseating of the cone it against the seat l5. During this time interval, the discharge of the com- Ipressor I' will be vented or unloaded through the vent l8. However, when the arm 20 reaches its uppermost position the cone 16 will be seated pot structure 28 so that the arm 20 will move slowly and the lapse of a definite period 01 time will. be provided between the energizing or the j motor 5 and theclosing of the valve i3 by the against *thetvalve seat 15 and thecompressor will be loaded'; Thetime interval provided by the retarding of the movement of thearm 20 attain full speed becapacityf and'forcompressors 'of large'size and capacity it becomes practically impossible'to passv a sufiicient quantity of "air 'or gas through the valve i3, for properly unloading the compressor.

Toprovide for the'properunloading of -compressors of larger sizes or capacities than can'be eflectorque load thereon 5 tively unloaded by the structure illustrated in Fig. 1, the modifled form of the unloading mechanism as illustrated in Fig. 2, is provided.

In this modified form of construction, it is to be understood that it is applicable for use with compressors of relatively small size in compari-v son with the larger type industrial compressor. In this form the compressor 40 includes the piston 4| which reciprocates in the cylinder 42 andis operated by the electric motor 43 through the medium of any suitable type of power transmission mechanism. The compressor 40 has an intake valve 44 and a discharge valve 45. The cylinder 42 is provided with a discharge passage or chamber 45 from which the fluid compressed passes into ,the pipe 41. From the pipe 41 the compressed fluid passes to the receiver 48: If it is so desired a check valve 49 the pipe 41.

For unloading the compressor 40, the suction valve 44 has an unloading piston 50 connected thereto which reciprocates in the cylinder L When the piston 50 is moved inwardly towards the end of the cylinder 42 it opens or holds open the suction valve 44 to permit the compressor 45 to operate in an unloaded or non-compressing condition.

The operation of the piston 55 is controlled by the control mechanism 52. The control mechanism 52 includes the valve structure 53 which is similar to the valve structure 13, diflering therefrom in details of construction. The valve structure 53 comprises the cylinder 54 which has two valve seats 55 and 55 formed therein which are engaged by the valve cones 51 and 55 respectively. The valve cones 51 and 58 are connected by a stem 59 and a second stem 50 is connected to the valve cone 58 and projects out of the cylinder 54 into the path of the operating arm 51. One end of the cylinder 54 is connected, through the pipe 52 with the pipe 41 or to the receiver the inlet pipe".

48 so that fluid compressed, under receiver-pressure may flow into pne end of the cylinder. A pipe 53 is connected to the interior of the cylinder 54 intermediate 01 its end and to the cylinder 5| so that when the valve cone 51 is 03 its seat, pressure fluid under'receiver-pressure may flow through the pipe 52, cylinder 54, pipe 53 into the cylinder 5| for holding open the suction valve 44. When the valve cone 51 is seated against its valve seat 55 and the cone 58 isofl the valve seat 55, the interior of the cylinder 51 is then opened through the pipe 53 into the cylinder 54 and vented either to atmosphere or to the suction of the compressor 40 through the vent 54.

' The valve operating arm 5| is similar to the valve operating arm 20 and it is in turn operated by the 'electromagnet or solenoid structure 55, which is just the same as the structure 25 and operates in the same manner for providing the lapsed time interval between the starting of the motor 43 and the loading oi the compressor.

The compressor is of approved type having a water Jacket for cooling processes. The cooling water. enters the water jacket through I A diaphragm operated valve 12 of any approved construction controls the supply of cooling water to the water Jacket 15 of the compressor. The diaphragm operated valve 12 is pressure operated, and is connected by the pipe 13 to the pipe 52 so that when the compressor is unloaded, the supply or cooling water to the watei jagket 15 will be cut oil.

may be placed in by said electrical means.

. tain the compressor in an unloaded state for a short time interval after the power is again out to the motor for operating the compressor, after which the compressor will be eilectively loaded 'until the power is again cut oil.

It will be understood that the invention is not to, b limited to the specific construction or arrangemen't of parts shown but that they may be widely'modifled within the invention deflned by the claims.

What is claimed is:

1. In a compressor unloading mechanism, the combination, of a compressor, an electric motor for'operating the compressor, a valve for controlling the loading and unloading of the compressor, a pivoted lever connected to said valve for positively operating said valve, electrical means connected in circuit with said motor for moving said lever in one direction, means independently 01' said electrical means connected to said lever for moving it in the direction reversely to the direction of movement of the lever 2. In a compressor unloading mechanism, the combination,.of a compressor, an electric motor for operating the compressor, a valve for controlling the loading and unloading of ,the compressor, a pivoted lever connected to said valve to the direction of movement oi. the lever by said electrical means, and means associated with said lever for retarding its movement by said independent means.

3. In a compressor unloading mechanism, the combination, of a compressor, an electric motor for operating said compressor, pressure operated means for unloading said compressor, a valve for delivering pressure fluid to said compressor unloading means, a. pivoted lever connected to said valve for'positively operating said valve, electrical means connected incircuitwith said motor for moving said lever in one direction, means independently of said electric means connected to said lever for moving it in the direction reversely to the direction of movement of the'lever by said electrical means.

4. In a. compressor unloading mechanism, the combination, of a compressor, an electric motor for operating said compressor, pressure operated means for unloading said compressor, a valve for 'delivering pressure fluid to 'said compressor unloading means, a pivoted lever connected to said valve for positigely operating said valve, electrical means connected in circuit with said motor to the direction of movement of the lever by saidelectrical means, and means associated with said lever for retardingdts movement by said independent means.

{EDWARD M. PAULLIN;'Jii. 

